KR20130054254A - Heat exchanger - Google Patents

Abstract

According to the invention, a heat exchanger 1 having an exchanger unit 20 is provided, the exchanger unit 20 of which the first and second wound conduits 21-23 are substantially coaxial in configuration. A casing 2 comprising one or more and for receiving the exchanger unit 20. The casing 2 has a first end wall 3, a second end wall 4, and a periphery 5 between these two end walls 3, 4. Each conduit 21-23 has an inlet and an outlet, and the outlets of the first conduits 21, 23 are connected substantially in series with the inlet of the second conduit 22. The plurality of wound conduits 21-23 is larger than the diameter of the turn of the first conduit 21 such that the third conduit 23 forms a spiral from which the helix formed by the first conduit 21 extends. And a third conduit 23 for the first fluid having a large diameter turn. The third conduit 23 has an inlet 23a and an outlet 23b, and the outlet 23b of the third conduit 23 is parallel to the first conduit 21 of the second conduit 22. It is preferred that the second conduit 22 is connected to the inlet 22a and the second conduit 22 has a larger flow cross section than the flow cross sections of the first and third conduits 21 and 23.

Description

Heat Exchanger {HEAT EXCHANGER}

The present invention relates to a heat exchanger, in particular a heat exchanger of the condensation type.

The function of the heat exchanger is to transfer thermal energy between the two fluids, for example in the case of a domestic gas boiler, the function of the heat exchanger is a hot fume produced from the combustion generated by the burner. Is to heat the water circulating inside the heat exchanger. Such boilers are considered to utilize both the heat generated after combustion and the latent heat of condensation contained in the combustion fumes. In order to recover the heat contained in the mist, the heat exchanger includes a casing in which there is a circulation path of water therein and the mist flows along it.

The amount of heat of condensation recovered is usually dependent on the temperature at which heat enters the heat exchanger and water is recovered and transferred from the heat exchanger. In addition, it is necessary to have a heat-exchange surface as long as possible in order to obtain significant heat exchange between the fluid inside and outside the path of the heat exchanger. For this purpose, the above-mentioned path may comprise a plurality of coiled conduits or tubes, the plurality of coiled conduits or tubes being arranged in a substantially coaxial manner with respect to one another. The innermost conduit of the plurality of conduits surrounds the burner.

In the first type of solution, the wound conduits are operated in parallel, ie each conduit is inlet chamber and outlet chamber of a heat exchanger formed at two axial ends of the corresponding casing. Extends between). A solution of this type is known from publication WO 2005/080900.

In the second type of solution, the solution of the present invention, a number of wound conduits are connected in series via a substantially U-shaped connector, thus conduits in which water is arranged in series. It enters from the inlet of the first conduit and passes into the heat exchanger and exits from the heat exchanger and passes through the outlet of the last conduit arranged in series. A solution of this type is known from publication EP-A-1 813 882, wherein the preamble of claim 1 is based on the European patent.

Known heat exchangers with wound conduits arranged in series are generally difficult to handle and somewhat complex to manufacture.

In addition, in such known heat exchangers, the helix formed by the multiple wound conduits is packed between two end walls opposite each other of the casing. This entails the need to consider thermal insulators with considerable weight in the end walls mentioned above. Moreover, this type of solution cannot be flexible in manufacturing given the fact that the axial dimensions of the casing of the heat exchanger are determined by the axial values of the wound conduit. As mentioned above, the thermal power of the heat exchanger, among other factors, depends on the surface of the heat exchanger, and thus is considered for different thermal power, without having to be further complicated in manufacturing and manufacturing costs. The heat exchangers differ in the number of turns of the various conduits and thus differ in the axial value of the corresponding helix, and because at least in the numerical value of the peripheral part, since the helix is sandwiched between the two walls of the casing, The casing must be intentionally made for each model of the heat exchanger, with mist discharge and inlet and water outlet connectors generally formed within the periphery.

These known solutions have the further drawback that the test step can be carried out only when the heat exchanger is actually completely assembled, ie only when the wound conduit set is mounted in the casing. If there are defects in manufacturing (for example, liquid leaks due to incomplete welds or seals), the product must be dismantled at least partly, which is time and costly.

Moreover, in general, the construction of known heat exchangers in which a number of wound conduits are arranged in series is a side on which user equipment, such as boilers or water heaters, can be installed, for example due to the inlet and outlet connectors of the water. Can't have flexibility in

In view of the foregoing considerations, the main object of the present invention, despite having small values, is to provide a heat exchanger which is simple and economically advantageous to ensure and manufacture the efficiency of operation.

An additional object of the present invention is to provide a heat exchanger having high flexibility in both aspects of manufacture and installation. Another additional object of the present invention is to provide a thermal ventilation that is easy to test.

In view of the above-mentioned main objects, the subject matter of the present invention is constructed integrally with the technical spirit provided herein for the invention and has the features described in the following claims, in particular a heat exchanger of the condensation type. Qi.

Further objects, features and advantages of the present invention will become apparent from the following detailed description, which is described with reference to the accompanying drawings, which are provided by way of non-limiting examples.
1 and 2 are perspective views showing a heat exchanger according to the present invention.
3 is a front view of the heat exchanger of FIGS. 1 and 2.
4 and 5 are enlarged cross-sectional views taken along lines IV-IV and VV of FIG. 3.
6 and 7 are exploded views of parts of the heat exchanger of FIGS. 1 and 2 and shown at different angles.
8 and 9 are views illustrating different angles by disassembling and reducing the heat exchanger of FIGS. 1 and 2.
10 and 11 are perspective views showing the wound conduit set of the heat exchanger of FIGS. 1 and 2 at different angles.
12 and 13 are front and rear views of the heat exchanger of FIGS. 1 and 2, with the front wall and casing body removed, respectively.
14 and 15 are perspective views illustrating hydraulic connection members of the heat exchanger of FIGS. 1 and 2.
16 is a front elevational view of the heat exchanger according to FIGS. 1 and 2, in which a corresponding burner is further provided.
FIG. 17 is a cross-sectional view taken along the line XVII-XVII of FIG. 16.
18 illustrates an exchanger unit according to a variant of the invention.
19 illustrates a plurality of exchanger units comprising a plurality of units according to FIG. 18.

Reference herein to "embodiment" or "an embodiment" indicates that a particular configuration, structure, or characteristic described with respect to the embodiment includes one or more embodiments. It is to raise. Thus, sentences such as "one embodiment" or "an embodiment," which may appear in different aspects of the above description of the invention, do not necessarily refer to one embodiment and the same embodiment. Moreover, certain shapes, configurations Or features may be combined with one or more embodiments in a suitable manner, and the references used herein are for convenience only and are not intended to limit the spirit or scope of the embodiments of the invention.

The heat exchanger for a gas boiler, in particular a condenser type heat exchanger, made in accordance with the invention is indicated by the reference numeral 1 in the figure.

The heat exchanger 1 has a casing 2 with two end walls 3 and 4 (defined herein as front and rear walls), and a periphery 5 extending between the two walls 3 and 4. ). In the illustrated example, the walls 3 and 4 are substantially quadrangular in shape and the periphery 5 has four side walls perpendicular to each other; In one variant (not shown), the end walls have a circular shape and the perimeter consists of one cylindrical wall.

In a preferred embodiment, the rear wall 4 and the perimeter 5 are made of a unitary body and are indicated by the reference 6. The unitary body 6 is preferably formed of molded plastic or synthetic material, for example polypropylene. The front wall 3 can preferably be joined to the upper edge of the perimeter 5 of the body 6 by caulking, which will be explained below.

The mist discharge part 7 and the condensation discharge part 8 are formed in the periphery 5, preferably, not necessarily in the regions opposite the periphery 5, the discharge parts being the casing 2. Substantially radial with respect to the axis. It is clear that the position of the outlets 7 and / or 8 may differ from the position in the embodiment. In addition, the unitary body 6 is integral with the fixing flange 10 as well as a ribbing or stiffening formation 9, for example a component at the edge of the periphery 5. It is preferred to integrate.

The wall 3 is made of a thermally conductive material, preferably stainless steel, which can be obtained by deforming a metal sheet by shearing and deformation processes. The wall 3 has a central passage 11 which is drawn somewhat inwardly, in particular for installing a burner (for example the burner is indicated by the reference numeral 50). See FIGS. 16 and 17). Preferably, a stiffening drawing 11a surrounding the opening 11 is provided to prevent deformation following installation of the burner. The reinforcement drawing 11a may support a fixing pin of the burner.

For fluids, in particular water, which are supposed to be heated, the hydraulic connecting member 12 of the heat exchanger 1 is fixed to the outside of the wall 3 in a position peripheral to the passage 11. do. The hydraulic connecting member 12 is fixed near the corner of the wall 3.

As will be explained more clearly below, the member 12 has two inner conduits and operates as an inlet connector and an outlet connector for the liquid. In the following, both the inlet and the outlet for the liquid of the heat exchanger 1 are located on one and the same end wall, namely the front wall 3, and preferably, it does not necessarily have to be adjacent to each other. Will be obvious.

The casing 2 houses an exchanger unit, the exchanger unit forming a heat-exchange path for the liquid and having a plurality of coiled conduits substantially coaxial. coiled conduit). The above mentioned exchanger unit is generally indicated by reference numeral 20 in FIGS. 4-7, which exchange unit is indicated by reference numerals 21, 22 and 23 in FIGS. 4, 5 and 8, 9, for example. Three or more wound metal tubes or conduits. Conduits 21 and 22, for example, conduits made of steel, for example, have coils of different diameters, which are formed by conduits 21 as can be clearly seen in FIGS. 4 and 5. It forms a spiral that extends within the helix. The conduit 23 has a larger diameter turn than the turn of the conduit 21 to form a spiral from which the helix formed by the conduit 21 extends. Each conduit 21-23 has a plurality of inlets 21a, 22a, 23a and outlets 21b, 22b and 23b (FIGS. 10 and 11).

According to the invention, the conduits 21 and 23 are arranged in parallel with each other and in series with respect to the conduit 22, ie the outlets of the conduits 21 and 23 ( 21b and 23b are connected to the inlet 22a of the conduit 22. The outermost conduits 21 and 23 are connected to the inner conduit 22 by a manifold member, which will be described below. In a preferred embodiment of the present invention, the passage section or flow section of the conduit 22 is larger than the flow section of the conduit 23 and preferably has the same flow cross section but is not necessary. none. In other embodiments the three conduits 21, 22 and 23 can have the same diameter as the flow cross section, but in this embodiment show a slightly lower level of performance.

In condensation heat exchangers of the type having a plurality of coaxial spirals, most of the heat generated through the burners (about 80%) is generated in the conduit forming the innermost spiral. According to the proposed solution to this, an inner conduit 22 having a larger diameter by two conduits 21 and 23 arranged in parallel and having a smaller diameter realizes greater efficiency, and an appropriate flow rate of fluid rate) and thus the numerical value of the unit 20 is kept compact throughout.

The actual test carried out by the present invention, when providing the heat exchanger 1 for domestic boiler use, conduits 21 and 23 having a flow cross section corresponding to a diameter of between about 12 mm and about 20 mm, in particular about 16 mm, And using a conduit 22 having a flow cross section corresponding to a diameter of between about 14 mm and about 22 mm, in particular about 16 mm, makes it possible to obtain very efficient operation.

In a particularly preferred embodiment, the three conduits 21-23 have a cross section in the form such that each helix has substantially the same pitch. This solution is particularly advantageous for production purposes, which will be explained below.

For example, in representative embodiments, as can be seen in FIGS. 4 and 5, conduits 21 and 23 have a generally circular cross section, while conduits 22 are generally ovalized or flattened. It has a cross section. As can be seen in FIG. 5, the oval cross section of the conduit 22 generally has a minor axis Y parallel to the corresponding helix axis, which spiral is substantially the circular cross section of the conduits 21 and 23. Corresponding to the diameter D of, in this way, a constant pitch P for three helices is obtained. Of course, the same result can be obtained with conduits 21-23 having different types of cross sections. According to one embodiment (not shown), the conduits 22 forming the inner helix of the unit 20 have a substantially rounded cross section, while the conduits 21 or conduits 21 and 23 are generally oval or It has a smaller flow cross section than the flow cross section of the flat conduit 22. Thus, in this kind of variant, the generally oval cross section or flat cross section of the conduit 21 or of the conduits 21 and 23 has a major axis which is generally parallel to the corresponding helix axis. It substantially corresponds to the diameter of the circular cross section of the conduit 22.

As can be seen in FIGS. 4 and 5, due to the constant pitch P, the axial values of the helix formed by the conduits of the unit 20 are the same (basically, the three helixes are of the same height), For the same reason, the number of turns of the various spirals is the same.

Preferably the distance between each turn is the same. To this end, in one embodiment, each wound conduit has suitable means for maintaining each turn at a right distance, preferably constant along the helix itself. In a particularly preferred embodiment, this means is constituted by localized portions of the conduit itself shaped to function as a spacer. In particular, according to the principle of document WO 2005/080900, the local parts can be obtained through modification of the corresponding conduit.

4 and 5, in the heat exchanger 1, how the spirals formed by two adjacent conduits can be arranged at a constant distance from each other so that a substantially cylindrical gap is formed between the two conduits. You can see if For this purpose, it is preferable that the turns of each spiral have the same diameter. 4 and 5, the interstice formed between turns of one helix is either directed toward the gap of the substantially adjacent spiral or aligned side by side with the gap of the adjacent spiral (ie the gap of one spiral is for example from above). Not towards the turn of adjacent spirals, as in the document EP-A-1 813 882 mentioned). The actual test performed by the present invention in any case ensures that this arrangement ensures the efficient operation of the heat exchanger 1.

In a preferred embodiment, the inlets 21a, 23a of the conduits 21, 23 and the outlets 22b of the conduit 22 are substantially positioned at the end wall 3 of the casing 2 as described below. do.

To this end, as can be seen clearly in FIGS. 6 and 10, in a representative embodiment, each conduit has an angled intermediate bend, which is indicated by reference numeral 21c,. 22c and 23b). In this way, an initial stretch of each conduit is formed in conduits 21 and 23, which are denoted by reference numerals 21d and 23d and generally extend axially or correspondingly. Extending in the direction of the height of the spiral, and similarly, a final stretch of the conduit is formed in the conduit 22, which is indicated by reference 22d and generally extends in the axial direction, or Extend in the direction of the height of the corresponding helix.

In a preferred embodiment, the extensions 21d, 22d and 23d of the above-mentioned conduits are substantially rectilinear, as well as substantially parallel to each other and parallel to the helix axis formed by each conduit. In addition, the extensions 21d, 22d and 23d of the conduits mentioned above extend outwardly of the helix formed by the outermost conduit 23 and substantially one area and one area of the wall 3 of the casing 2 ( It is preferable to reach 3a) (see eg FIGS. 1 and 2), ie to reach the area in which the connecting member 12 is mounted. However, as can be seen in a representative preferred embodiment, the stretches mentioned above extend from the ends of the helix opposite to the wall 3.

Conduits 21 and 23 are connected to conduits 22 by manifold members mounted at the inlet end of conduit 22 and the outlet ends of conduits 21 and 23.

In one embodiment, the manifold member mentioned above generally includes a caplike body similar to the cap indicated by reference numeral 24 in FIGS. 5, 8, 9, 12, and 13. The body similar to the cap 24 (preferably made of a metallic material, but not necessarily made of a metallic material) has a shape in which at least a portion is bent to form an inner surface, the inner surface being generally In the bent and mounted state, it faces the inlet 22a of the conduit 22 and toward the outlets 21b and 23b of the conduits 21 and 23.

In the illustrated example, the manifold member further comprises a plate element made of a metallic material, as can be seen, for example, in FIGS. 25). The plate element generally has a flat central portion, in which three through holes (see FIGS. 8 and 9), and a body similar to the cap 24 in a fluid-tight manner (24). Peripheral edges are formed that are configured to engage. When both the edge of the plate 25 and the cap-like body 24 are made of metal, the edge between the plate 25 and the cap-like body 24 are joined in such a way that the fluid does not leak, for example by welding. Can be. For assembly, the ends of the conduits 21-23 are inserted into the above-mentioned through-holes and are then fixed to the plate 25 in a leak-tight manner, in particular by welding, as seen for example in FIG. have.

In one embodiment, the outlet end of the conduits 21 and 23 and the inlet end of the conduit 22, which should be secured to the plate 25, are cut with an inclined cut as seen in FIG. Cut. This feature improves the hydrodynamic characteristics of the manifold member and reduces head loss, a similar function being obtained due to the curvature of the inner surface of the body 24, which is similar to the cap. It is apparent that the through-holes formed in the plate 25 have a cross section and a uniform cross section determined by the inclined cut plane of the conduit.

In a preferred embodiment, the exchanger unit 20 comprises one or more first end plates, denoted by reference numeral 26, as seen, for example, in FIGS. 4, 5, 8, 9 and 12. In the assembled state of the heat exchanger 1, the plate 26 faces the wall 3 of the casing 2 and is in contact with the wall 3. The plate 26 may be manufactured, for example, by shearing and drawing into a metal sheet, and to connect with the passage 11 of the wall 3, FIGS. 8, 9 and 12. Each central passage is indicated at 27. In order to connect the two passages 11 and 27, at least one of the two passages is formed by a generally tubular portion of the plate 26 or the wall 3, in the example illustrated above, The tubular part belongs to plate 26 and is indicated by reference numeral 26a in FIGS. 4 and 5. On the other hand, as mentioned above, the inner edge of the wall 3 forming the opening 11 is slightly drawn inwards, as can be seen in FIGS. 4 and 5. In the assembled state, the upper part of the tubular part 26a of the plate 26 delimits the wall 3, in particular the opening 11, in such a way that no fluid leaks by welding. It is fixed at the edge.

As can be seen, the plate 26 generally has an annular flange portion 26b (FIGS. 4 and 5) from which the tubular portion 26a rises, End turns of the conduits 21-23 rest over the flange portion 26b.

In the assembled state, the annular portion 26b of the plate 26 is arranged at a distance from the wall 3 of the casing so that a generally annular gap is formed between the plate and the wall. For example, as can be seen in FIGS. 4 and 5, the gap is indicated by reference numeral 28 and may be such that the temperature of the wall 3 is maintained even without insulating mass. The reason for this is that the plate 26 is only coupled to the wall 11 only at the upper edge of the tubular portion 26a and the end turns of the conduit are in direct contact with the wall 11. In addition, during operation of the heat exchanger 1, through the gaps between the turns of the conduits 21-23, fumes can reach the outside of the unit 20, whereby the gaps 28 are substantially It will be appreciated that it can be dried and produced most of the heat in the conduit and thus correspondingly cooled in the gap region between the plate 26 and the wall 3.

As mentioned earlier, in the assembled state, the end turns of the conduits 21-23 are in contact with the plate 26. The plate 26 is preferably shaped to form a seat or depression in order to position the end turns of the helix formed by the conduits 21-23, some of which sheet or depression. Is denoted 29 by FIG. In this example, the sheet 29 has a terminal part that is substantially straight with a prevalent part that is shaped substantially similarly to an arc of circumference, the terminal part. Extends almost tangentially. The seat 29 makes it possible to properly position the corresponding helix according to the end turns mentioned above, and the tangential stretch of the seat 29 mentioned above allows each of the straight portions of the conduit to be conduit 23. (See FIGS. 10-12), the manifold member 23-25 mentioned above is provided at the end of said portions of the conduit, as far as possible to position the helix formed as far as possible.

In a preferred embodiment of the invention, the unit 20 comprises a second end plate, indicated by reference numeral 30 in FIGS. 4, 5, 8, 9 and 13, wherein the second end plate 30 is a plate ( It is preferably produced in a manner substantially similar to 26) but without the central opening. In the assembled state, the second end plate 30 faces the wall 4 of the casing 2 and is arranged at a distance from the wall 4 of the casing 2. Spiral end turns opposite the wall 3 are arranged above the second end plate 30. In addition, the second end plate 30 is provided with a corresponding placement sheet 31, for example as shown in FIG. 13, the placement sheet 31 is in the shape and function of the sheet 29 of the plate 26. Has similar shape and function. Further, in this case, the tangential extension of the sheet 31 allows the position of each of the straight portions of the conduit to be positioned as far as possible out of the helix formed by the conduit 23, with an angled intermediate portion at the end of the portion. Bends 21c, 22c and 23c are provided (see eg FIGS. 7 and 13).

In a preferred embodiment, the exchanger unit 20 is supported by the end wall 3 of the casing 2, ie by the same wall where the inlet and outlet for liquids that can flow through the heat exchanger 1 are located. .

For this purpose, the unit 20 preferably comprises a tie-shaped support element which is supported by the wall 3 at one end and which supports a set of conduits 21-23 at the other end. In the illustrated non-limiting example, the tie mentioned above (indicated by reference numeral 32 in FIGS. 8 and 9 and only a portion of the tie is illustrated) passes the set of conduits 21-23 through the plate 30. And is indirectly supported by the wall 3 through the plate 26.

As mentioned above, the spirals formed by two adjacent conduits of the unit 20 are arranged at a constant distance from each other to form a substantially cylindrical gap between the two conduits. The tie 32 extends in the gap substantially in the axial direction of the spiral formed by the conduits 21-23. This solution makes it possible to laterally enclose the unit 20 and to axially stabilize the set of spirals.

The tie 32 is formed of a metal sheet and preferably has a flat surface in general. To engage the tie, plates 26 and 30 have respective slits, although not shown in the figure. The tie 32 is initially substantially straight in shape and is mounted to pass through the slits of the plates 26 and 30 for assembly. From the plates 26 and 30, the ends of the ties 32 protruding toward the walls 3 and 4, respectively, are bent at substantially right angles, as can be clearly seen in FIGS. 12 and 13, for example. It is preferred to complete by welding the bent end of the tie 32 and secure it to the corresponding plate 26 or 30.

14 and 15 illustrate the connecting member 12 fixed to the outside of the wall 3 at a position corresponding to the area 3a where the ends of the conduits 21-23 to be connected outward are located. The connecting member 12 has a metal or plastic body and forms two conduits 12a and 12b. The conduit 12a should be connected to the outlet 22b of the conduit 22 and has a flow cross section substantially the same as the flow cross section of the conduit 22, while the conduit 12b has an inlet and the flow cross section of the inlet Substantially the same as the flow cross section of conduit 12a, branching off to two outlets 12c, which outlet 12c has a flow cross section substantially the same as the flow cross sections of conduits 21 and 23; The outlet portion 12c is arranged at a portion connected to the inlets 21a and 23a of the conduit.

The process of manufacturing the components of the heat exchanger 1 is simple. As mentioned above, the body 6 of the casing can be obtained by molding a thermoplastic material, for example polypropylene. Walls 3, plates 26 and 30, and ties 32 start from metal sheets and may be obtained through shearing and / or deformation processes using techniques that are consolidated in sectors. Can be. In addition, the metal conduits 21-23 can be obtained in the described shape using techniques known in the sector. The manufacturing process of the components 24 and 25 of the body of the connecting member 12 and of the manifold member is also simple.

In addition, the assembly of the heat exchanger 1 is also very simple and at least part of it can be automated.

The first end of the tie 32 passes through the corresponding slit of the plate 26, which is then bent at an angle and welded to the plate itself. The helix formed by the three conduits 21-23 is coaxially formed over the plate 26 such that the helix matches the shape of the sheet 29 (FIG. 12) and the tie 32 extends in one or more gaps formed between adjacent helices. Arraged coaxially. Between the plate 26 and the turn of the first end of the helix, a sealant material, for example a silicone material resistant to high temperatures, can be arranged.

The second end of the tie 32 then fits into the corresponding slit of the plate 30 and comes into contact with the turn of the second end of the spiral so as to match the shape of the seat 31 (FIG. 13). ). Before placing and securing the plate 30, an insulating body, denoted by reference numeral 34 in FIGS. 4-5 and 8-9 and made of, for example, ceramic fibers or vermiculite, is provided with a conduit ( It is preferred to be inserted into the bottom opening of the spiral formed by 22 in an interference fit manner. Thereafter, the second end of the tie 32 is bent and welded to the plate 30. Also in this case, a seal of the type mentioned above can be arranged between the turn of the second end of the helix, the heat insulator 34 and the plate 30.

In this way, the conduits 21-23 are packed between the plates 26 and 30. As mentioned above, in combination with the ties 32, the sheets 29 and 32 of the plates 26 and 30 allow for the proper placement of the helix. In this case, the plates 26 and 30 are shaped so that they can be aligned side by side between turns of several helixes in a direction substantially perpendicular to the helix axis, for which the plates 29 and 31 are formed. The area 26 and 30 extends over at least a portion as a coil and starts and ends at a small inclined wall (as can be seen in Figures 8 and 9).

The unit 20 first arranges the plate 25 in the corresponding end region of the conduits 21-23, as mentioned above (FIGS. 10-11), and then through the corresponding welding, the distributor Completed with distributor member 23-25. The body 24, which is similar to the cap, is then associated with the plate 25 in this case in such a way that the fluid does not leak, for example by welding.

Once the unit 20 is assembled, the ends of the elongations of the conduits 21d-23d protrude at a height above the helix, as can be seen, for example, in FIGS. 10 and 11. The ends of the conduits 21-23 are then inserted into respective holes provided in the area 3a (see FIG. 7) to project slightly beyond the wall 3. On the wall 3, the connecting member 12 uses a screw or the like, for example, and a seal ring is interposed, corresponding to the region 3a and the end of the conduit. Conduit 12b-12c (FIG. 14-15) is in communication with inlets 21a and 23a of conduits 21 and 23 and conduit 12a is thus conduit Communicate with the discharge portion 22b of 22. Finally, the edge of the tubular portion 26a of the plate 26 is welded along the flared inner edge of the opening 11 of the wall 3.

This unit can be inserted towards the inside of the body 6 until the peripheral edge of the wall 3 is arranged over the edge of the peripheral part 5. The edge of the wall 3 is directly caked over the edge of the periphery 5 (in the figure the state of engagement before the caking operation is shown). To this end, the edge of the perimeter 5 of the plastic body 6 has a peripheral flange, which is indicated by reference 5a in FIGS. 4-7 and protrudes outwards, the wall 3 mentioned above. It is shaped to provide a peripheral sheet 3b into which one flange 5a is inserted. The outer edge of the wall 3 can be caulked over the flange 5a without the need to insert any seal element in a position corresponding to the sheet 3b.

Referring now to Figs. 16 and 17, the operation of the heat exchanger 1 with a gas boiler of the domestic type in the heat exchanger itself will be briefly described. In this case, the first heat exchange fluid is, for example, a heating liquid to be circulated in the radiator system, or water in a sanitary system, and the second heat exchange fluid is fumes generated by combustion.

The liquid that must be heated out of the system is introduced into the heat exchanger 1 through the conduit 12b of the connecting member 12. By bifurcated conduit 12b, the liquid is supplied to conduits 21 and 23 arranged in parallel until reaching the manifold members 24-25. Through the manifold member, the water exiting the conduits 21 and 23 is transferred into the conduit 22. This liquid then flows through the helix closest to the conduit 22 or burner 50 to reach the conduit 12a of the connecting member 12.

Due to the two cross sections of the different passages, liquid with different flow rates passes in an amount proportional to the heat exchange capacity of each conduit, with the three conduits 21-23 starting from the hottest inner conduit 22 It operates at a separate and descending temperature towards the coldest outermost conduit 23, thus favoring the manner of determining condensation of the fumes. In each conduit, the liquid tries to absorb different amounts of heat, the majority of the heat being absorbed by the innermost conduit 22, which absorbs heat by radiation generated by the burner 50, and the intermediate conduit 21 and the outermost conduit 23 absorb residual energy of the fumes. Due to the low temperatures of the conduits 21 and 23, it is possible to absorb very large amounts of energy from the fumes and to efficiently condense by encountering progressively impoverished and increasingly cold liquids. .

Thereafter, the liquid discharged from the conduit 12a of the connecting member 12 is reintroduced into the system. The condensate produced in the heat exchanger 1 is collected and discharged through the discharge section 8, and the residual fumes are discharged through the discharge section 7.

The heat exchanger 1 as a whole is highly efficient recycling with a minimum amount of fiber insulation, etc., through the molding of plastic materials (when the body 6 is made of the material) as well as a simple shearing and deformation process of the metal sheet. It can be made of a material. Assembly of the components is similarly simple.

The configuration of the heat exchanger is quite compact, and at the same time, the fluid is properly flown using two wound outer conduits to ensure high thermal efficiency, and is supplied to a single inner conduit wound in parallel.

The proposed solution offers broad flexibility with respect to the problem of selecting the material that should be used to manufacture the unit 20 to optimize the cost-to-performance ratio. For example, the outer conduit can be made of a material that has a lower value than the inner conduit and / or is resistant to corrosion (as mentioned earlier, the outer conduit is less heat, but More exposed) and may be made of a material that is less resistant to heat than the material used for internal conduit applications. Similarly, the thicknesses of the conduits can be different, for example, the outer conduits are thinner than the inner conduits, for example.

The fact that the exchanger unit is substantially "self-supporting", i.e., entirely supported by a single wall of the casing, makes it possible to use a single identical casing body and obtain a heat exchanger for different thermal power. For example, if all other conditions are the same, the previously described components with nine turns of spirals in conduits 21-23 may be used. While having a power of 32 kW, conduits 21-23 of the same element but only six turns allow a 20 kW heat exchanger to be obtained and continue depending on the number of turns selected. This exchanger unit 20 can in any case be combined with a casing 2 of the same type, which has obvious advantages in terms of fabrication. Points are increased apparently because of the solution to consider the constant pitch (P) according the same axial levels on the various spirals of the various spiral.

Due to the fact that the exchanger unit is supported by a single wall of the casing, there is an advantage of reducing the number of insulators. This advantage is further increased because there is an annular gap 28 and there are advantages coming from heating the wall 3.

Unlike the exchanger according to the prior art, the support of the exchanger unit by a single end wall of the casing determines the practical advantage of enabling the unit 20 to be tested before being inserted into the casing 2. Thus, possible defects in fabrication can be corrected simply and quickly.

The advantages mentioned above also relate to the fact that the inlet and outlet of the fluid are located on the same end wall that supports the exchanger unit. This feature provides even more flexibility when installing heat exchangers in the final application. For example, the wall 3 is simple angular rotation with respect to the periphery 5, the entire unit 20 and thus the connecting member, so that alternative positions, in particular the mist discharge 7 and the condensation discharge 9, are provided. You will need to understand that you can have a location for. This feature proves to be useful because, as mentioned above, it is possible to modify the position of the connector 12 depending on the field of final application for various types of boilers.

Of course, under the principles of the present invention, the embodiments and detailed configurations may be widely changed to the embodiments described and illustrated herein by way of example only, without departing from the scope of the present invention.

In the exemplary embodiment described above, the axis of the heat exchanger 1 is arranged in the horizontal direction but should not be considered limited only thereto. Similarly, the present invention should not be understood to be limited to household type products, such as boilers, water heaters, etc., and it should be noted that the heat exchanger according to the present invention can in fact be used in other fields as well. do.

In the illustrated embodiment, the inlet and outlet of the heat exchanger are arranged close to each other in the wall 3, but should not be understood to be limited only to this type of positional arrangement. In fact, by appropriately shaping the conduits 21-23, the inlet and outlet occupy positions set such that they are spaced apart from one another, for example, the inlet is located close to the first corner of the wall 3. And the outlet portion is arranged at a position proximate to the second corner portion of the wall 3, for example, the second corner portion is opposite in the diagonal direction with respect to the first corner portion.

The confluence of the outlets 21b, 23b of the conduit 23 into a single outlet conduit is similar to that described previously for the conduits 12b-12c of the connecting member 12 and the two inlets. By considering a suitable header with one outlet, it is possible to be obtained in the casing 2.

The body 6 may be made of a metal material, for example steel, instead of plastic.

FIG. 18 illustrates a unit 20, with conduits forming inlets 21a and 23a and outlet 22b on one side and outlets 21b and 23b and inlet 22a on the other side. The terminal stretch of (21-23) has a rectilinear configuration and, in the former case, extends substantially radially on the outside of the helix formed by the outermost conduit 23. ‹‹ ¤ with a changed position for This type of form has the advantage of producing a unit formed by a plurality of exchanger units, ie a plurality of units 20 connected to each other. One application of this kind is illustrated in FIG. 19. In Fig. 19, the same reference numerals are used as those used in the previous figures to indicate elements which are technically equivalent to the elements already described, and primed to easily distinguish them from the inlets and outlets of the various units. ') Symbol and a secondary prime (") symbol are added.

In this example, the plurality of units includes, as an example, three units 20, 20 'and 20 "which are identical to each other. In this example, the outlet of the conduits 21, 23 of the unit 20 21b and 23b are connected in parallel to the inlets 22a of the corresponding conduits 22 using respective manifolds, and the outlets 21b 'and the outlets 21 and 23 of the conduits 21 and 23 of the unit 20'. 23b 'is connected in parallel to the inlet 22a' of the corresponding conduit 22 via each manifold, and similarly the outlet 21b "of the conduits 21, 23 of the unit 20". And 23b ") are connected in parallel via respective manifolds to the inlets 22a" of the corresponding conduits 22. The manifolds used for connecting in parallel can be configured, for example, of the type described above. It can, but not necessarily.

In this example, the delivery branches of the plurality of units in FIG. 19 are constituted by outlets 22b, 22b 'and 22b "of units 20, 20' and 20", which are known in the art. It is manufactured in the art of parallel connection with each other via a suitable manifold (not shown). Similarly, the return branches of a plurality of units mentioned above are defined by inlets 21a + 23a, 21a '+ 23a' and 21a "+ 23a" of units 20, 20 'and 20 ". The return branches are connected in parallel to one another via a suitable manifold (not shown) which can be obtained by known techniques.

As can be seen herein, the present invention is a heat exchanger having a higher power and larger size than the heat exchanger described for FIGS. 1-17, for example, an industrial or commercial type heating system. It may be advantageous to be used for the preparation. The configuration of a "multiple" heat exchanger differs in many aspects from the configuration of the heat exchanger illustrated in FIGS. 1-17, with the advantage that a specific connection between conduits 21 and 23 and conduit 22 is achieved. This ensures efficiency and miniaturization. Also in this case, the axes of the plurality of units can be arranged in the vertical direction, of course, the number of turns of the conduits 21-23 of the unit 20 used is changed for the case illustrated here by way of example only. May be

Claims (15)

Heat exchanger, especially as a condensation heat exchanger,
The heat exchanger is:
An exchanger unit 20 comprising a plurality of wound conduits 21-23 which are coaxial with one another for the first fluid, the plurality of wound conduits 21-23 comprising a single first conduit ( 21) and one or more of one second conduit 22 and a third conduit 23, wherein the first, second and third conduits 21-23 have coils of different diameters, and a second Conduit 22 forms a spiral that extends within the helix formed by first conduits 21, 23, and third conduit 23 draws a spiral within the spiral formed by first conduit 21. Form;
A casing 2 for receiving the exchanger unit 20, the casing 2 between the first end wall 3, the second end wall 4 and the two end walls 3, 4. Having a periphery 5, wherein the casing 2 is configured to receive a second fluid for heat exchange with the first fluid, the first end wall 3 having a through opening 11, in particular a burner 50. Has a through opening 11 for);
Each conduit 21-23 has inlets 21a, 22a, 23a and outlets 21b, 22b, 23b, with outlets 21b, 23b of the first conduits 21, 23 being second. In a heat exchanger connected in series with an inlet portion 22a of a conduit 22,
The outlet 23b of the third conduit 23 is connected to the inlet 22a of the second conduit 22 in parallel with the first conduit 21 and the flow of the second conduit 22. The heat section is larger than the flow cross section of the first conduit 21 and larger than the flow cross section of the third conduit 23. The method of claim 1,
The second conduit 22 has a larger flow cross section than the flow cross sections of the first and third conduits 21, 23;
The first, second and third conduits 21-23 have a cross sectional shape such that each helix has the same pitch P, in particular the first and third conduits 21, 23 are circular cross sections. And the second conduit 22 has an ovalized or flattened cross section, the oval cross section of the second conduit 22 has a minor axis (Y) parallel to the corresponding spiral axis. Heat exchanger, characterized in that it is equal to the diameter (D) of the circular cross section of the first and third conduits (21, 23). 3. The method according to claim 1 or 2,
The exchanger unit 20 is supported by the first end wall 3 of the casing 2,
The inlet part 21a of the first conduit 21, the inlet part 23a of the third conduit 23 and the outlet part 22b of the second conduit 22 comprise the first end wall of the casing 2. Heat exchanger, characterized in that located in 3). The method according to any one of claims 1 to 3,
Each conduit 21-23 has an intermediate bend 21c-23c angled to form an initial extension 21d, 23d of the conduit or a final extension 22d of the conduit, respectively; Heat exchanger, characterized in that the final extension (22d) extends in the axial direction of the corresponding helix. The method of claim 4, wherein
The elongations 21d-23d of the conduits are straight, parallel to each other, in particular parallel to each other, parallel to the helix axis formed by the respective conduits 21-23, and the outermost of the conduits 21-23. A heat exchanger, characterized in that it extends out of the spiral formed by the conduit (22). 3. The method according to claim 1 or 2,
A helix formed by two adjacent ones of said conduits (21-23) is spaced apart from each other such that a cylindrical gap is formed between said two adjacent conduits. The method according to claim 6,
The exchanger unit (20) is characterized in that it comprises a plurality of tie elements (32) extending in the cylindrical gap in the axial direction of the helix formed by the conduits (21-23). 3. The method according to claim 1 or 2,
The exchanger unit 20 comprises one first end plate 26, the first end plate 26 being coaxial and having a through opening in the first wall 3 of the casing 2. 11 with respective through openings 27 connected towards the first wall 3 of the casing 2, one or more of the openings being tubular of the first plate 26 or of the first wall 3. Formed by the part 26a, the first plate 26 is fixed to the first wall 3, in particular by welding,
The coils at the first end of the spiral formed by conduits 21-23 are in contact with the first plate 26,
At least one annular portion 26b of the first plate 26 is separated from the first wall 3 of the casing 2 so that the annular portion 26b and the first wall of the first plate 26 are Heat exchanger, characterized in that the annular gap (28) is formed between (3). The method of claim 8,
The exchanger unit 20 includes a second end plate 30, which faces the second wall 4 of the casing 2, which is spaced apart from each other, and the conduits 21-23. Heat exchanger, characterized in that the coils at the second end of the spiral formed by) are in contact with the second plate (30). 10. The method according to any one of claims 7 to 9,
The tie element 32 has opposite ends fixed to the first and second plates 26, 30, respectively, and the plates 26, 30 are in particular through slots for the tie element 32. Heat exchanger having a). 3. The method of claim 2,
The heat exchanger comprises a connector member 12 mounted on the first wall 3 of the casing 2, which connector first 12 forms first and second passages 12a, 12b, and the first The passage 12a is connected to the outlet 22b of the second conduit 22 and the second passage 12b is connected to the inlets 21a and 23a of the first and third conduits 21 and 23, respectively. A heat exchanger having two outlets (12c) and an inlet. 3. The method according to claim 1 or 2,
The heat exchanger is connected to the inlet end 22a of the second conduit 22 and the outlet end 21b of the first conduit 21 or to the outlet ends 21b and 23b of the first and third conduits 21 and 23, respectively. Includes a mounted manifold member 24-25,
The manifold member 24-25 is:
A cap body (24) forming a curved surface facing the inlet end (22a) and the outlet end or the outlet end (21b, 23b);
Characterized in that the inlet end 22a and the outlet end or the outlet end 21b, 23b have at least one of a plate element 25 with a through opening, in particular sealing secured by welding. heat transmitter. 13. The method of claim 12,
Heat exchanger, characterized in that the conduit (21-23) is cut at the inlet end (22a) and the outlet end or end (21b, 23b) in an inclined cut. 3. The method according to claim 1 or 2,
Heat exchanger characterized in that it comprises a plurality of exchanger units (20, 20 ', 20 ") connected to each other. 15. The method of claim 14,
In each of said units 20, 20 ', 20 ", the outlets 23b, 23b', 23b" of the third conduit 23 are the outlets 21b, 21b 'of the first conduit 21, 21b ") in parallel with the inlets 22a, 22a ', 22a" of the second conduit 22,
The outlets 22b, 22b ', 22b "of the second conduit 22 of the units 20, 20', 20" are connected in parallel,
The inlets 22a, 22a ', 22a "; 23a, 23a', 23a" of the first and third conduits 21, 23 of the units 20, 20 ', 20 "are connected in parallel Heat exchanger characterized by the above.

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